This open-label, randomized study in HIV-seropositive persons with CD4 cells between 100 and 500/mm(3) will compare the safety, efficacy and pharmacokinetics of two formulation of saquinarvir, a proteinase inhibitor of HIV replication. The formulation and dosage currently in use (saquinarvir hard gel capsules at 600 mg po tid) will be compared to a new formulation (saquinarvir soft gel capsules at 400,800 or 1200 mg po tid). It is hoped that he new formulation will have better oral bioavailibility than the current formulation and will be well tolerated and efficacious. Endpoint measurements will include HIV RNA, CD4 cell counts and any clinical adverse events.